Automatic transmissions for motor vehicles commonly use torque-converter couplings with planetary gear units that can supply one or two gear reductions and reverse, depending on the design, by simultaneously engaging or locking various elements of the planetary gear unit. Typically, a simple planetary gear unit includes a sun gear, a ring gear, and a carrier which supports a plurality of shafts on which are mounted planet or pinion gears. The planetary gearset carrier provides the structure to carry torque through the pinion gears and shafts to an output member, and therefore must be rigid enough to provide gear location without deflection.
Conventional planet carriers are known which are either one piece castings, castings fastened together such as by riveting, or steel multi-piece constructions joined together by laser welding or electron beam welding. For example, the A4LD carrier used by Ford Motor Company, the assignee of the present invention, utilizes a stamped plate having a bent leg which is capacity discharge welded onto radial projections in a hub portion of the carrier.